RTP-area local music and culture

[grady <grady AT ibiblio.org>]

Sound transmission across the broadest range of frequencies is a 
function of mass above all else, so that's why I recommended ICFs (the 
fact that you work for a concrete contractor sounds like a bonus to me, 
assuming you can get a deal on the pumper truck).

I don't have #s on ICFs vs staggered-stud, but I'd lay money that ICF 
will perform better. I'd be curious to see any comparison you found 
online, though, for sure.

Plus if you somehow still wound up with issues, you could add an 
interior stud wall (although I'd be taking extra care to look at 
openings, both around doors & also any wall penetrations (electric, 
plumbing, HVAC, etc) first)

Depending on the size of the room, you may very well be driven quickly 
deaf by all the HF reflections, but knocking down HF that's bouncing 
around is something that's less difficult -- depending on the frequency, 
anything from a couple of inches of compressed fiberglass to yr good 
old-fashioned carpet scraps, etc.

Here's a random site with a sound absorption table for a wide range of 
surfaces (scroll down a bit): http://www.cowanaudio.com/acoustic.html

Once you get in there & start playing, you can determine what kind of 
treatment you need. If you're getting killed by stuff around 1khz, for 
instance, acoustic tile, carpet or heavy drapes look pretty good, but 
compressed fiberglass looks even better.

There are plans on the internet for building what are essentially big 
shallow plywood boxes that you load compressed-fiberglass sheets into, 
then cover with chicken-wire and burlap. I built a bunch for WXDU years 
& years ago & they help a lot.

The good thing about absorbing/diffusing reflections is that *any* 
amount of material you install in the space helps . . . you don't have 
to uniformly cover every surface.

The other alternative to all of this, of course, is to build a bomb 
shelter underground in the backyard. Future occupants of your house 
would doubtless find that to be pretty kewl. ;-)

Good luck!

Ross


Michel Inserny wrote:
> This room will only serve the band practice purpose. Yes, I would use any
> construction technique available to make the room to serve its purpose (I
> play the drums, so I need to practice without annoying neighbors, and I need
> to have a band practice space where I could practice for several hours at
> night, few nights a week with no issues) If I'm going to spend the money in
> the project I need it to work.
>
> I didn't think of ICF before, cause somehow I thought staggered stud walls
> with insulation in between would provide better sound proofing than ICF.
> I'll check again though.
>
> Since I work for a concrete contractor, the idea was to build a slab on
> grade. However, would you put any type of flooring above that (for better
> acoustics?)
>
> Also, I wasn't thinking of having any windows and when I get to construction
> phase I will get all permits and stuff. Right now I'm at the engineering and
> design phase and the plan is to have this done by July.
>
>
> Thanks for your help.
>
> Michel
>
> On Fri, Feb 12, 2010 at 10:37 AM, grady <grady AT ibiblio.org> wrote:
>
> > One word: mass
> >
> > Another word: seal all openings (wait, that was three words)
> >
> > Do you have any intention at all of making this a multipurpose space? Do
> > you have the ability/desire to use any construction techniques available
> > to you?
> >
> > If I were building a box solely to keep sound in, I'd do the following:
> >
> > 1) slab-on-grade construction
> > 2) walls made out of ICFs (Insulating Concrete Forms):
> > http://www.forms.org/
> > 3) no windows (sorry! no view for you!)
> > 4) Doubled doors (one framed to be flush with the exterior wall & the
> > other to be flush with the interior wall) with heavy weatherstripping
> >
> > The roof/ceiling structure might actually be trickiest, but if you use
> > double drywall on the ceiling & then load up on the insulation above,
> > you'd probably be OK.
> >
> > If you're just looking for *attenuation* as opposed to major
> > soundproofing, then you can start eliminating items from that list.
> >
> > You still have to adhere to the basic rules of thumb, though: sound is
> > going to exit the structure either through holes (even tiny ones) or by
> > vibrating the walls of the structure itself. So you have to seal all the
> > holes, and you have to make the walls of the structure massive enough
> > that your drums/amps can't effectively make them vibrate. Or decouple
> > the interior & exterior walls enough that if the interior ones vibrate,
> > the exterior ones don't.
> >
> > Ross
> >
> > James Hepler wrote:
> > > OK, so you're building a structure from scratch, and you have all
> > necessary
> > > permits and everything?  I just want to be clear that what I'm picturing
> > in
> > > my head is what you have in mind.
> > >
> > > * Windows:  The single best way to limit the amount of sound that
> > permeates
> > > will be number and sizes of windows.  If you can limit that, you're off
> > to a
> > > great start.  but then you have climate control to think about.  So
> > planning
> > > is obviously key.
> > >
> > > I really hope I'm not sounding condescending.  I'm thinking in print.
> > >
> > > * If you're building from scratch, you have the luxury of putting most of
> > > your sound dampening material inside the walls.  I would think that some
> > > good, dense insulation would be pretty much all you need in order to keep
> > > sound in.  I mean, I practice in my guest room, and while neighbors two
> > > doors down can hear THAT we're practicing when they're in their back
> > yards,
> > > nothing makes it through both sets of walls, and I have crappy insulation
> > if
> > > I have any at all.
> > >
> > > It seems like it would be pretty easy to get your outside walls put up
> > and
> > > insulation installed and then test it out.
> > >
> > > I don't think it would take much to get everything within the parameters
> > of
> > > local ordinances. This is all I can think of, and others are way smart
> > and
> > > more experienced when it comes to this stuff than me.  Listen to them.
> > Good
> > > luck!
> > >
> > >
> > >
> > >
> > > On Fri, Feb 12, 2010 at 8:51 AM, Michel Inserny <minserny AT gmail.com>
> > wrote:
> > > > Good morning fellas,
> > > >
> > > > I'm sure this has been discussed in the past, but I'm trying to get some
> > > > help building a band practice space in my back yard. Has anybody done
> > > > something similar that can give me some contacts, web links, telephone
> > > > numbers, etc to get some advice as of what's the best way to sound
> > > > attenuate/proof new construction so my neighbors dont complain when I
> > play
> > > > music in that room?
> > > >
> > > > This will be a new, independent building that will be a little more than
> > > > 100
> > > > ft away from any neighbor, and I need to make 100% sure it works for the
> > > > purpose.
> > > >
> > > > Thanks,
> > > >
> > > > Michel
> > > > -- ch-scene: the list that mirrors alt.music.chapel-hill --
> > > > http://lists.ibiblio.org/mailman/listinfo/ch-scene
> > -- ch-scene: the list that mirrors alt.music.chapel-hill --
> > http://lists.ibiblio.org/mailman/listinfo/ch-scene
> -- ch-scene: the list that mirrors alt.music.chapel-hill --
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